Radio wave receiving systems have been developed for a variety of uses. For instance, radio wave receiving systems have been developed for the transmission of images. In conventional systems, an antenna receives image information contained on a “received signal.” The information is acquired by converting the received signal into an intermediate wave, amplifying the intermediate wave, and then detecting the image information (see Japanese Patent Laid-open No. 07-191151A2 or the like).
Under certain conditions, these conventional systems may not acquire accurate information via the radio waves. For instance, signal noise may detrimentally affect the receiving system's ability to acquire information. Specifically, if the signal level of the noise is greater than the signal level of the received signal, then the information contained in the received signal is less likely to be acquired properly. This problem is especially apparent in passive systems that receive radio waves radiated from a target region.
Furthermore, temperature fluctuations may detrimentally affect the ability of the receiving system to acquire information. Specifically, if the temperature of the receiving system fluctuates, signal levels may, in turn, fluctuate. Accordingly, these signal level fluctuations may detrimentally affect the receiving system's ability to accurately acquire information.